"To Senator Ensign: Please continue to defend our conservative values with all your vigor, particularly our Second Amendment! Thank you," the note read.
Mazzola said it was the first time someone had used that method to contact the senator.
"People call, write, e-mail and even fax our office, but this is certainly a first," he said.
"Now we have another example comparing Capitol Hill to high school: recess, cafeterias, bells, attendance checks and now note-passing," Mazzola said.
"Senator Ensign appreciates the kind words of support, but he can't take all the credit. It's a credit to overwhelming support from 61 other senators who stood up for Second Amendment rights and voted for his bill."